function $tag(uri,tag){
	var uri=objURI(uri);
	var svcTag=Components.classes["@mozilla.org/browser/tagging-service;1"].getService(Components.interfaces.nsITaggingService);
	if(tag){
		svcTag.tagURI(uri, tag);
	}else{
		return svcTag.getTagsForURI(uri, {});
	}
}